Piercing tool and retainer therefor



w. H. PECK PIERCINGv TOOL AND RETAINER THEREFOR Sept. 10, 1963 Filed Aug. 28, 1962 INVENTOR. WILLIAM H. PECK ATTORNE Y United States Patent I O l 3,103,367 PIERCING TOOL AND RETAINER THEREFOR William H. Peck, 314 N. Center St, Royal Oak, Mich. Filed Aug. 28, 1962, Ser. No. 219,852 4 Claims. (Cl. 279-76) This invention relates to a tool such as a chisel, piercing punch or the like, and a retainer therefor particularly adapted for use with a pneumatic hammer or percussion type gun.

The tool herein selected for illustrating the invention is shown as a punch for piercing holes in sheet metal members, after which self tapping screws are threaded into the hole.

In forming holes through the sheet metal member in this manner, the punch is provided with a sharp pointed piercing nose which is pierced through the metal by a series of percussion blows at the opposite end of the tool. The pointed piercing nose spreads the metal and flares a flange on the back side surface of the metal, thereby increasing the thread area for the screw, and since the nose is driven into the metal by the hammer blows it is tightly held in the hole causing resistance to its removal. The operator is required to tip the axis of the tool from one side to the other to remove the tool, resulting in distortion of the hole.

It is an object of the present invention to provide means on the shank of the tool, cooperating with the tool retainer, for producing oscillatory movement to the tool while it is driven into the metal and when a pulling force is applied to the tool in removing it fromthe hole, thereby facilitating its removal without tipping the axis of the tool.

Another object of the invention is to provide a tool retainer which'will permit limited axial movement of the tool with respect to the axis of the retainer. I A further object of the invention is to provide means on the shank of the tool, cooperating with the tool retainer for properly positioning the tool within the retainer so that the oscillatory movement means between the tool and retainer is properly aligned when the tool is inserted in the retainer.

Other objects and advantages of the invention will more fully appear from the following detailed description taken in connection with the accompanying drawings in which:

FIG. 1 is a side elevational view of a pneumatic hammer showing the improved punch applied to the retainer;

FIG. 2 is a side elevational view of the tool;

FIG. 3 is a cross sectional view through the tool taken on line 33 of FIG. 2;

FIG. 4 is an end view of FIG. 2;

FIG. 5 is a side elevational view of the ball retainer sleeve, a portion thereof being broken away and in section;

FIG. 6 is a longitudinal cross sectional view of the locking sleeve;

FIG. 7 is a longitudinal cross sectional view of the tool retainer showing the shank of the tool inserted in the retainer;

FIG. 8 is an end view of the tool and its retainer; and

FIG. 9 is a cross sectional view taken on line 9-9 of FIG. 7.

Referring to the drawings, I have shown a pneumatic hammer 10, having a barrel :12 and a handle 14. The handle has a connection 16 for communication with an air pressure line 18 connected to a source of pressure, not shown. A control is shown at 20 for admitting the air pressure to the operating parts of the hammer which are of conventional construction. The tool, herein illustrated as a punch, is received in the open end of the retainer, more clearly shown in FIG. 7.

The tool retainer includes a ball cage sleeve 24 hav- Patented Sept. 10, 19 63 ice ing an axial bore therethrough for receiving the tool 22 which has a'sliding fit therein. The outer diameter of the ball cage sleeve 24 is provided with a groove 26 for receiving a snap washer 28 having an outer diameter greater than the outer diameter of the ball cage sleeve 24. One endof the ball cage sleeve 24 has its outer diameter reduced, as at 30, providing a shoulder 32 which limits the inward movement of the retainer against the outer end of the barrel 12 when the reduced end 60 is press fitted into a bore 34 in the open end of the barrel 12. If desired the ball cage sleeve 24 may be formed as an integral part of the open end of the pneumatic hammer barrel :12.

Ball receiving apertures 36 are formed in the wall of the ball cage sleeve 24 for the reception of balls 38 having a diameter greater than the Wall thickness of the ball cage sleeve 24. The apertures 36 are preferably tapered inwardly to prevent the balls from passing entirely through the apertures;

The apertures 36 are elongated longitudinally of the ball cage sleeve 24 and extend in a slightly helical angle to the axis of the-ball cage sleeve 24. The ball cage sleeve 24 is further provided with ball receiving depressions 40 in its outer penipherial surface, here shown as four. The reduced end portion 30 of the ball cage sleeve 24 is provided with an aperture 42 extending through the wall thereof. This aperture has an inwardly tapered surface and receives a ball 44 having a diameter greater than the inner diameter of the aperture 4-2 at its inner end to prevent the ball 44 from passing through the aperture 42, but to project beyond the inner periphery of the ball cage sleeve 24.

A locking sleeve 46 is rotatably mounted on the ball cage sleeve 24 between the snap washer 28 and the reduced portion 30. This sleeve 46 is provided with oppositely disposed apertures 48 through the wall thereof slightly less than the diameter of the balls 38 so that the balls may only partially enter the apertures 48. The sleeve 46 is further provided with an aperture 50 for receiving a ball 52. The aperture is tapered inwardly to a diameter slightly less than the diameter of the ball 52 to permit the ball to only partially pass through the inner diameter of the sleeve 46 for reception in one of the ball receiving depressions 40 in the ball cage sleeve 24. The ball '52 is held in the aperture 50 by a split spring band 54.

The tool 22 herein illustrated is a round, hard steel member having a straight shank portion '56 with a sharp pointed punch portion 58 projecting from one end thereof. This projection 58 has a major diameter at the flat end portion 60 tapering outwardly to a sharp point. The major diameter is curved outwardly to produce a curved edge on the hole formed in a sheet metal member so that the screw is easily inserted in the hole and provides an increased thread area. The opposite end 62 of the tool is formed flat to receive the impact blows of the well known pneumatic hammer. Intermediate the opposite endsof the tool are oppositely disposed annular depressions 64 formed in the peripherial surface of the tool for receiving a portion of the balls 38. A concave groove 66 is formed in the peripherial surface of the tool through the end 62 and extends in a helical angle corresponding to the angle of the helical apertures 36 and is of a length corresponding to the length of the apertures 36 terminating in longitudinal alignment with the adjacent end of one of the apertures 3-6. The groove 66 is for reception of the ball 44.

With the retainer assembled on the pneumatic hammer and the sleeve 46 turned relative to the ball cage sleeve 24 with the apertures 48 aligned with the balls 38, the flat end 62 of the tool is inserted into the open end of the retainer until the flat end 62 strikes the ball 44. Then the tool is manually rotated until the open end of the groove 66 is aligned with the ball 44. The tool is then inserted farther into the open end of the retainer until the closed end of the groove 66 strikes the ball 44. The tool is then in proper position for the balls 38 to drop into the depressions 64 after which the sleeve 46 is given a quarter of a revolution on the ball cage sleeve 24 moving the spring pressed ball 52 to the next circumferentially spaced depression 40. The balls 38 are held in the depressions 64 by the inner peripheral wall of the sleeve 46. When it is desired to remove the tool, the sleeve 46 is given another quarter turn to radially align the apertures 48 with the balls 38, the balls 38 being partially received in the apertures 48 and out of the depressions 64. The locating groove 66 cooperating with the ball 44 makes it very easy to properly position the tool in the retainer with the balls 38 aligned with the depressions 64. Otherwise, it would be necessary to resort to a fishing expedition to properly align the balls 38 in both a circumferential and axial direction with respect to the apertures 48.

The tool is free for limited axial movement within the bore through the ball cage sleeve 24 determined by the length of the apertures 36 but is retained therein by the ends of the apertures 36 engaging the balls 38 which are carried axially of the ball cage sleeve 24 along with the axial movement of the tool. Since the apertures 36 extend in a helical direction, the tool is oscillated during its axial movement relative to the retainer and pneumatic hammer. I

When piercing a hole through a metal member, the operator presses the pointed end 58 of the tool on the metal. This pressure forces the tool inwardly of the tool retainer and when the hammer is operated the percussions within the hammer force the tool outwardly, driving the pointed end 58 through the metal. When the operator removes the tool from the metal by a pull, the action causes the tool to he slid outwardly relative to the retainer, and due to the helical arrangement of the grooves 36, the tool is oscillated to loosen the point in the hole formed in the metal.

It will be understood that various changes in the size, shape and arrangement of parts may be made without departing from the spirit of the invention and it is my intention to cover in the appended claims such changes as may be reasonably made within a fair interpretation of the meaning of the terms in the appended claims.

I claim:

1. A tool for use in a pneumatic hammer of the percussion type ior producing holes wherein percussion blows are applied to one end of the tool, comprising a straight bar body portion having a flat end face at one end thereof for receiving percussion blows and a sharp projection at the opposite end thereof for producing holes in a member, the outer surface of said body portion being smooth and annular except for an annular ball receiving depression in the outer periphery of the body of said tool intermediate its opposite ends, and a helical concave groove in the outer periphery of the body of said tool extending through said flat end face.

2. A tool for use in a pneumatic hammer of the percussion type for producing holes wherein percussion blows are applied to one end of the tool, comprising a straight harr body portion having a flat end face at one end thereof for receiving percussion blows and a sharp projection at the opposite end thereof for producing holes in a member, the outer surface of said body portion being smooth and annular except for an annular ball receiving depression in the outer periphery of the body of said tool intermediate its opposite ends, and a helical concave groove in the outer periphery of the body of said tool extending through said flat end face, and having its closed end extending toward said annular ball receiving depression and in axial alignment with said annular hail receiving depression.

3. A tool for use in a pneumatic hammer of the percussion type having a straight annular body portion, an annular ball receiving depression in the peripheral surface of said body portion intermediate its opposite ends, a helical concave groove in the peripheral surface of said tool and extending through the end surface which is received in a retainer, in combination with a retainer having a ball cage sleeve, a helical slot through the wall of said sleeve, a ball in said slot having a diameter greater than the thickness of the wall of said sleeve, said sleeve being further provided with an aperture through the wall thereof, a ball in the aperture having a diameter greater than wall thickness of said sleeve, said first named ball adapted for reception in the annular depression formed in said tool and said last named ball adapted for reception in the helical concave groove in said tool, and a rotatable lock-ing sleeve surrounding said ball cage sleeve, said locking sleeve being provided with an aperture through the wall thereof having a diameter less than the diameter of said first named hall.

4. A tool for use in a pneumatic hammer of the percussion type having a straight annular body portion, an annular ball receiving depression in the peripheral surface of said body portion intermediate its opposite ends, -a concave groove in the periphenal surface of said tool and extending through the end surface which is received in a retainer, in combination with a retainer having a ball cage sleeve, a slot through the Wall of said sleeve, a hall in said slot having a diameter greater than the thickness of the wall of said sleeve, said sleeve being further provided with an aperture through the wall thereof, a ball in the aperture having a diameter greater than the wall thickness of said sleeve, said first named ball adapted for reception in the annular depression formed in said tool and said last named hall adapted for reception in the concave groove in said tool, and a rotatable locking sleeve surrounding said ball cage sleeve, said lockingsleeve being provided with an aperture through the wall thereof having a diameter less than the diameter of said first named ball.

References Cited in the file of this patent UNITED STATES PATENTS 2,448,995 MrcCorkhill Sept. 7, 1948 2,638,807- I Sharman May 19, 1953 2,947,334 Issa-rtel Aug. 2, 1960 2,982,556 Peck May 2, 1961 

4. A TOOL FOR USE IN A PNEUMATIC HAMMER OF THE PERCUSSION TYPE HAVING A STRAIGHT ANNULAR BODY PORTION, AN ANNULAR BALL RECEIVING DEPRESSION IN THE PERIPHERAL SURFACE OF SAID BODY PORTION INTERMEDIATE ITS OPPOSITE ENDS, A CONCAVE GROOVE IN THE PERIPHERAL SURFACE OF SAID TOOL AND EXTENDING THROUGH THE END SURFACE WHICH IS RECEIVED IN A RETAINER, IN COMBINATION WITH A RETAINER HAVING A BALL CAGE SLEEVE, A SLOT THROUGH THE WALL OF SAID SLEEVE, A BALL IN SAID SLOT HAVING A DIAMETER GREATER THAN THE THICKNESS OF THE WALL OF SAID SLEEVE, SAID SLEEVE BEING FURTHER PROVIDED WITH AN APERTURE THROUGH THE WALL THEREOF, A BALL IN THE APERTURE HAVING A DIAMETER GREATER THAN THE WALL THICKNESS OF SAID SLEEVE, SAID FIRST NAMED BALL ADAPTED FOR RECEPTION IN THE ANNULAR DEPRESSION FORMED IN SAID TOOL AND SAID LAST NAMED BALL ADAPTED FOR RECEPTION IN THE CONCAVE GROOVE IN SAID TOOL, AND A ROTATABLE LOCKING SLEEVE SURROUNDING SAID BALL CAGE SLEEVE, SAID LOCKING SLEEVE BEING PROVIDED WITH AN APERTURE THROUGH THE WALL THEREOF HAVING A DIAMETER LESS THAN THE DIAMETER OF SAID FIRST NAMED BALL. 